// Seed to get repeatable colors
var seed = null;

// Shared color dictionary
var colorDictionary = {};

// Populate the color dictionary
loadColorBounds();

// check if a range is taken
var colorRanges = [];

var randomColor = function (options) {

    options = options || {};

    // Check if there is a seed and ensure it's an
    // integer. Otherwise, reset the seed value.
    if (options.seed !== undefined && options.seed !== null && options.seed === parseInt(options.seed, 10)) {
        seed = options.seed;

        // A string was passed as a seed
    } else if (typeof options.seed === 'string') {
        seed = stringToInteger(options.seed);

        // Something was passed as a seed but it wasn't an integer or string
    } else if (options.seed !== undefined && options.seed !== null) {
        throw new TypeError('The seed value must be an integer or string');

        // No seed, reset the value outside.
    } else {
        seed = null;
    }

    var H,S,B;

    // Check if we need to generate multiple colors
    if (options.count !== null && options.count !== undefined) {

        var totalColors = options.count,
            colors = [];
        // Value false at index i means the range i is not taken yet.
        for (var i = 0; i < options.count; i++) {
            colorRanges.push(false)
        }
        options.count = null;

        while (totalColors > colors.length) {

            // Since we're generating multiple colors,
            // incremement the seed. Otherwise we'd just
            // generate the same color each time...
            if (seed && options.seed) options.seed += 1;

            colors.push(randomColor(options));
        }

        options.count = totalColors;

        return colors;
    }

    // First we pick a hue (H)
    H = pickHue(options);

    // Then use H to determine saturation (S)
    S = pickSaturation(H, options);

    // Then use S and H to determine brightness (B).
    B = pickBrightness(H, S, options);

    // Then we return the HSB color in the desired format
    return setFormat([H,S,B], options);
};

function pickHue(options) {
    if (colorRanges.length > 0) {
        var hueRange = getRealHueRange(options.hue)

        var hue = randomWithin(hueRange)

        //Each of colorRanges.length ranges has a length equal approximatelly one step
        var step = (hueRange[1] - hueRange[0]) / colorRanges.length

        var j = parseInt((hue - hueRange[0]) / step)

        //Check if the range j is taken
        if (colorRanges[j] === true) {
            j = (j + 2) % colorRanges.length
        }
        else {
            colorRanges[j] = true
        }

        var min = (hueRange[0] + j * step) % 359,
            max = (hueRange[0] + (j + 1) * step) % 359;

        hueRange = [min, max]

        hue = randomWithin(hueRange)

        if (hue < 0) {hue = 360 + hue;}
        return hue
    }
    else {
        var hueRange = getHueRange(options.hue)

        hue = randomWithin(hueRange);
        // Instead of storing red as two seperate ranges,
        // we group them, using negative numbers
        if (hue < 0) {
            hue = 360 + hue;
        }

        return hue;
    }
}

function pickSaturation (hue, options) {

    if (options.hue === 'monochrome') {
        return 0;
    }

    if (options.luminosity === 'random') {
        return randomWithin([0,100]);
    }

    var saturationRange = getSaturationRange(hue);

    var sMin = saturationRange[0],
        sMax = saturationRange[1];

    switch (options.luminosity) {

        case 'bright':
            sMin = 55;
            break;

        case 'dark':
            sMin = sMax - 10;
            break;

        case 'light':
            sMax = 55;
            break;
    }

    return randomWithin([sMin, sMax]);

}

function pickBrightness (H, S, options) {

    var bMin = getMinimumBrightness(H, S),
        bMax = 100;

    switch (options.luminosity) {

        case 'dark':
            bMax = bMin + 20;
            break;

        case 'light':
            bMin = (bMax + bMin)/2;
            break;

        case 'random':
            bMin = 0;
            bMax = 100;
            break;
    }

    return randomWithin([bMin, bMax]);
}

function setFormat (hsv, options) {

    switch (options.format) {

        case 'hsvArray':
            return hsv;

        case 'hslArray':
            return HSVtoHSL(hsv);

        case 'hsl':
            var hsl = HSVtoHSL(hsv);
            return 'hsl('+hsl[0]+', '+hsl[1]+'%, '+hsl[2]+'%)';

        case 'hsla':
            var hslColor = HSVtoHSL(hsv);
            var alpha = options.alpha || Math.random();
            return 'hsla('+hslColor[0]+', '+hslColor[1]+'%, '+hslColor[2]+'%, ' + alpha + ')';

        case 'rgbArray':
            return HSVtoRGB(hsv);

        case 'rgb':
            var rgb = HSVtoRGB(hsv);
            return 'rgb(' + rgb.join(', ') + ')';

        case 'rgba':
            var rgbColor = HSVtoRGB(hsv);
            var alpha = options.alpha || Math.random();
            return 'rgba(' + rgbColor.join(', ') + ', ' + alpha + ')';

        default:
            return HSVtoHex(hsv);
    }

}

function getMinimumBrightness(H, S) {

    var lowerBounds = getColorInfo(H).lowerBounds;

    for (var i = 0; i < lowerBounds.length - 1; i++) {

        var s1 = lowerBounds[i][0],
            v1 = lowerBounds[i][1];

        var s2 = lowerBounds[i+1][0],
            v2 = lowerBounds[i+1][1];

        if (S >= s1 && S <= s2) {

            var m = (v2 - v1)/(s2 - s1),
                b = v1 - m*s1;

            return m*S + b;
        }

    }

    return 0;
}

function getHueRange (colorInput) {

    if (typeof parseInt(colorInput) === 'number') {

        var number = parseInt(colorInput);

        if (number < 360 && number > 0) {
            return [number, number];
        }

    }

    if (typeof colorInput === 'string') {

        if (colorDictionary[colorInput]) {
            var color = colorDictionary[colorInput];
            if (color.hueRange) {return color.hueRange;}
        } else if (colorInput.match(/^#?([0-9A-F]{3}|[0-9A-F]{6})$/i)) {
            var hue = HexToHSB(colorInput)[0];
            return [ hue, hue ];
        }
    }

    return [0,360];

}

function getSaturationRange (hue) {
    return getColorInfo(hue).saturationRange;
}

function getColorInfo (hue) {

    // Maps red colors to make picking hue easier
    if (hue >= 334 && hue <= 360) {
        hue-= 360;
    }

    for (var colorName in colorDictionary) {
        var color = colorDictionary[colorName];
        if (color.hueRange &&
            hue >= color.hueRange[0] &&
            hue <= color.hueRange[1]) {
            return colorDictionary[colorName];
        }
    } return 'Color not found';
}

function randomWithin (range) {
    if (seed === null) {
        //generate random evenly destinct number from : https://martin.ankerl.com/2009/12/09/how-to-create-random-colors-programmatically/
        var golden_ratio = 0.618033988749895
        var r=Math.random()
        r += golden_ratio
        r %= 1
        return Math.floor(range[0] + r*(range[1] + 1 - range[0]));
    } else {
        //Seeded random algorithm from http://indiegamr.com/generate-repeatable-random-numbers-in-js/
        var max = range[1] || 1;
        var min = range[0] || 0;
        seed = (seed * 9301 + 49297) % 233280;
        var rnd = seed / 233280.0;
        return Math.floor(min + rnd * (max - min));
    }
}

function HSVtoHex (hsv){

    var rgb = HSVtoRGB(hsv);

    function componentToHex(c) {
        var hex = c.toString(16);
        return hex.length == 1 ? '0' + hex : hex;
    }

    var hex = '#' + componentToHex(rgb[0]) + componentToHex(rgb[1]) + componentToHex(rgb[2]);

    return hex;

}

function defineColor (name, hueRange, lowerBounds) {

    var sMin = lowerBounds[0][0],
        sMax = lowerBounds[lowerBounds.length - 1][0],

        bMin = lowerBounds[lowerBounds.length - 1][1],
        bMax = lowerBounds[0][1];

    colorDictionary[name] = {
        hueRange: hueRange,
        lowerBounds: lowerBounds,
        saturationRange: [sMin, sMax],
        brightnessRange: [bMin, bMax]
    };

}

function loadColorBounds () {

    defineColor(
        'monochrome',
        null,
        [[0,0],[100,0]]
    );

    defineColor(
        'red',
        [-26,18],
        [[20,100],[30,92],[40,89],[50,85],[60,78],[70,70],[80,60],[90,55],[100,50]]
    );

    defineColor(
        'orange',
        [19,46],
        [[20,100],[30,93],[40,88],[50,86],[60,85],[70,70],[100,70]]
    );

    defineColor(
        'yellow',
        [47,62],
        [[25,100],[40,94],[50,89],[60,86],[70,84],[80,82],[90,80],[100,75]]
    );

    defineColor(
        'green',
        [63,178],
        [[30,100],[40,90],[50,85],[60,81],[70,74],[80,64],[90,50],[100,40]]
    );

    defineColor(
        'blue',
        [179, 257],
        [[20,100],[30,86],[40,80],[50,74],[60,60],[70,52],[80,44],[90,39],[100,35]]
    );

    defineColor(
        'purple',
        [258, 282],
        [[20,100],[30,87],[40,79],[50,70],[60,65],[70,59],[80,52],[90,45],[100,42]]
    );

    defineColor(
        'pink',
        [283, 334],
        [[20,100],[30,90],[40,86],[60,84],[80,80],[90,75],[100,73]]
    );

}

function HSVtoRGB (hsv) {

    // this doesn't work for the values of 0 and 360
    // here's the hacky fix
    var h = hsv[0];
    if (h === 0) {h = 1;}
    if (h === 360) {h = 359;}

    // Rebase the h,s,v values
    h = h/360;
    var s = hsv[1]/100,
        v = hsv[2]/100;

    var h_i = Math.floor(h*6),
        f = h * 6 - h_i,
        p = v * (1 - s),
        q = v * (1 - f*s),
        t = v * (1 - (1 - f)*s),
        r = 256,
        g = 256,
        b = 256;

    switch(h_i) {
        case 0: r = v; g = t; b = p;  break;
        case 1: r = q; g = v; b = p;  break;
        case 2: r = p; g = v; b = t;  break;
        case 3: r = p; g = q; b = v;  break;
        case 4: r = t; g = p; b = v;  break;
        case 5: r = v; g = p; b = q;  break;
    }

    var result = [Math.floor(r*255), Math.floor(g*255), Math.floor(b*255)];
    return result;
}

function HexToHSB (hex) {
    hex = hex.replace(/^#/, '');
    hex = hex.length === 3 ? hex.replace(/(.)/g, '$1$1') : hex;

    var red = parseInt(hex.substr(0, 2), 16) / 255,
        green = parseInt(hex.substr(2, 2), 16) / 255,
        blue = parseInt(hex.substr(4, 2), 16) / 255;

    var cMax = Math.max(red, green, blue),
        delta = cMax - Math.min(red, green, blue),
        saturation = cMax ? (delta / cMax) : 0;

    switch (cMax) {
        case red: return [ 60 * (((green - blue) / delta) % 6) || 0, saturation, cMax ];
        case green: return [ 60 * (((blue - red) / delta) + 2) || 0, saturation, cMax ];
        case blue: return [ 60 * (((red - green) / delta) + 4) || 0, saturation, cMax ];
    }
}

function HSVtoHSL (hsv) {
    var h = hsv[0],
        s = hsv[1]/100,
        v = hsv[2]/100,
        k = (2-s)*v;

    return [
        h,
        Math.round(s*v / (k<1 ? k : 2-k) * 10000) / 100,
        k/2 * 100
    ];
}

function stringToInteger (string) {
    var total = 0
    for (var i = 0; i !== string.length; i++) {
        if (total >= Number.MAX_SAFE_INTEGER) break;
        total += string.charCodeAt(i)
    }
    return total
}

// get The range of given hue when options.count!=0
function getRealHueRange(colorHue)
{ if (!isNaN(colorHue)) {
    var number = parseInt(colorHue);

    if (number < 360 && number > 0) {
        return getColorInfo(colorHue).hueRange
    }
}
else if (typeof colorHue === 'string') {

    if (colorDictionary[colorHue]) {
        var color = colorDictionary[colorHue];

        if (color.hueRange) {
            return color.hueRange
        }
    } else if (colorHue.match(/^#?([0-9A-F]{3}|[0-9A-F]{6})$/i)) {
        var hue = HexToHSB(colorHue)[0]
        return getColorInfo(hue).hueRange
    }
}

    return [0,360]
}